1. Field of Invention
The present invention relates to dichroic filter and manufacturing methods therefor, and to direct-view display devices and projection display devices which include such color filters.
2. Description of Related Art
In color filters used in, for example, liquid crystal devices, absorbing filters which transmit light beams of a certain color and absorb beams of other colors, and reflective filters which transmit light beams of a certain color and reflect beams of other colors are known (for example, see Japanese Unexamined Patent Application Publication No. 9-325312). One of the known types of reflective filters is a dichroic filter which employs dielectric multilayer films.
In dichroic filters, the wavelength ranges for the transmitted light beams change depending on the layer structure of the dielectric multilayer film. By disposing three types of dichroic filters having transmitting wavelength ranges of, for example, R (red), G (green), and B (blue), respectively, color-filter arrays can be formed.
Dichroic filters exhibit (1) extremely high color purity; (2) no deterioration caused by, for example, light or heat since the filters are made of inorganic material; and (3) reusability of the reflected light by adjustment of the optical system.